The purpose of this project is to provide independent consultation on statistical and epidemiological methodology in the design, interpretation, and evaluation of clinical trials of diagnosis, treatment, and prevention of cancer, and other studies requiring this kind of expertise. For some studies the Section provides full statistical support, including development of detailed study plans; assistance in the design of appropriate study forms; supervision of randomization (for trials); collection, processing, and editing of data; performance of interim analyses during the progress of the study; preparation of progress reports; final analysis of study data; and collaboration in the preparation of scientific papers. Among the current projects are: HIV Prevention Trials. Consultation on intervention trial design is being provided to the NIAID via membership on several working groups dealing with various aspects of the prevention of HIV infection and AIDS. Analysis of USDA Feeding Studies. We are collaborating with the Cancer Prevention Studies Branch on the analysis of a series of USDA feeding studies of women 20-40 years of age. Research is underway to study the complex relationships between blood lipids, hormone levels, and plasma carotenoid levels by phase of the menstrual cycle. Polyp Prevention Trial. We are providing full statistical support for the design, conduct and analysis of a multicenter dietary intervention trial among 2,000 men and women with a previous adenomatous polyp of the colon or rectum. Biomarker Studies. We are providing consultation on the quality control aspects of serum hormone measurements in a dietary study among children, and on the effects of measurement error in biological assays of hormones on the results of epidemiologic studies. Study of the Adoption and Use of the Primary Care Nutrition Guide. The Section has provided statistical consultation to the Public Health Applications Research Branch on the design, planning, and implementation of a physician practice study evaluating the NCI Primary Care Nutrition Guide and a training course (based on the Guide) among internal medicine and family medicine practices. Working Well Project. In collaboration with the Prevention and Control Extramural Research Branch, the Coordinating Center, and the Evaluation Working Group, study endpoints (smoking and dietary) were defined, with particular emphasis on who should be included in the analysis. Other Projects. A number of other projects both within the DCPC and with many outside researchers such as the University of Texas, the University of Arkansas , the National Institute of Child Health and Human Development, the National Institute on Alcohol Abuse and Alcoholism, Harvard University, the Division of Cancer Treatment, the National Center for Health Statistics, and Battelle Pacific Northwest Laboratory are also being pursued.